岩石压缩系数的计算及其对气藏数值模拟结果的影响研究

岩石压缩系数是气藏工程中的一个重要参数,其取值影响着气藏数值模拟的计算结果。目前计算岩石压缩系数的方法有很多,在矿场上,最常用的计算方法是Hall图版经验公式法,但其计算结果与实际值有较大差距。文中对比分析了Hall图版经验公式法和弹性模量法,并研究了不同的计算方法对气藏数值模拟结果的影响。由Hall图版经验公式法计算得到的岩石压缩系数偏大,即对地层岩石的弹性能量估计偏大,从而导致气藏数值模拟计算的压降速度偏慢;而采用弹性模量法计算岩石压缩系数,其结果相对较为合理。

Calculation of rock compressibility and the impact on gas reservoir numerical simulation

Rock compressibility is an important parameter in gas reservoir engineering. It affects the results of gas reservoir numerical simulation. At present, there are many calculation methods of rock compressibility. In the mine field, the most commonly used method of calculation is Hall Plate empirical formula. But there is a wide gap between its results and the actual. The Hall Plate empirical formula and the elastic modulus method are comparatively analyzed, and the impacts of different calculation methods on gas reservoir numerical simulation results are studied. If rock compressibility is calculated by the elastic modulus method, its results are relatively reasonable. But if it is calculated by the Hall Plate empirical formula, the value of rock compressibility is too large. That＇ s to say, it overvalues the elastic energy of formation rocks. And the velocity of pressure drawdown of the gas reservoir numerical simulation is caused to be too slow.